A high proportion of magnetic concentrate with sintering oxidation catalyst and its use method
By preparing and adjusting the ratio of sintering oxidant and catalyst, the problem of incomplete oxidation of high-proportion magnetite concentrate during sintering was solved, resulting in reduced fuel consumption and improved sinter quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ANGANG STEEL CO LTD
- Filing Date
- 2026-02-06
- Publication Date
- 2026-05-29
Abstract
Description
Technical Field
[0001] This invention belongs to the field of sintering technology, and specifically relates to a sintering oxidation catalyst for high-proportion magnetic concentrate and its application method. Background Technology
[0002] The oxidation of magnetite is an exothermic reaction; therefore, adding magnetite concentrate to the sintering mixture can reduce fuel consumption. Typically, the sintering temperature is around 1300℃, the oxygen volume fraction in the exhaust air is about 21%, and the oxygen volume fraction in the tail gas is about 15%–18%. According to thermodynamic principles, magnetite can be oxidized to hematite under these conditions. However, when the proportion of magnetite concentrate in the sintering mixture is high, the low oxygen partial pressure generated by fuel combustion and other kinetic conditions unfavorable to the oxidation of magnetite concentrate make complete oxidation difficult. Furthermore, particle agglomeration and liquid phase formation during sintering also affect the oxidation kinetics of magnetite concentrate. When the temperature is above 900℃, magnetite concentrate can recrystallize and grow grains in the absence of oxygen. This reduces the porosity of the sintering particles and prevents oxygen diffusion to the reaction interface, thus reducing the oxidation rate of the magnetite concentrate. As the sintering temperature increases, a sintering liquid phase forms and coats the magnetite concentrate particles, further inhibiting oxygen diffusion to the reaction interface.
[0003] When the proportion of magnetite concentrate in the sintering mixture is high, magnetite cannot be completely oxidized to hematite. During sintering, both the Fe3O4-CaO-SiO2-Al2O3 and Fe2O3-CaO-SiO2-Al2O3 systems coexist, resulting in a reduced amount of SFCA (sulfate-free carbonaceous oxide). Therefore, sintering with high-proportion magnetite concentrate also relies on the aggregation and recrystallization between magnetite particles and silicate bonding. Furthermore, due to the poor reactivity of magnetite, higher temperatures are required to obtain a sufficient liquid phase to ensure sintering strength, which offsets the advantages of magnetite in reducing fuel consumption. Therefore, conditions need to be created to accelerate magnetite oxidation or increase its reactivity to promote the formation of the sintering liquid phase. Summary of the Invention
[0004] The purpose of this invention is to provide a sintering oxidation catalyst for high-proportion magnetite concentrate and its application method. By preparing a sintering oxidant, the oxidant addition ratio is optimized according to the iron concentrate ratio and the difference in the oxidizability of magnetite concentrate, thereby improving the oxidation reaction capacity of iron concentrate. Furthermore, by preparing a sintering catalyst, the combustion efficiency of solid fuel (carbon) is improved, the sintering oxidation kinetics of high-proportion magnetite concentrate are improved, and the sintering production efficiency and sinter quality are enhanced.
[0005] To achieve the above objectives, the present invention employs the following technical solution: A high-proportion magnetic concentrate sintering oxidation catalyst is composed of a sintering oxidant and a sintering catalyst. The raw materials for preparing the oxidant, by weight, include: 30-55 parts calcium peroxide, 25-45 parts magnesium peroxide, 2-15 parts potassium permanganate, and 2-12 parts calcium ferrate. The above raw materials are thoroughly mixed and ground to prepare the sintering oxidant. The raw materials for preparing the sintering catalyst, by weight, include: 30-60 parts dolomite, 20-40 parts iron powder, 10-20 parts rare earth tailings, and 5-15 parts sintering dust. The raw materials for preparing the sintering catalyst are thoroughly mixed and ground to prepare the sintering catalyst.
[0006] Furthermore, the particle size composition of the sintering oxidant is such that particles smaller than 0.074 mm account for more than 90 wt%.
[0007] Furthermore, the particle size composition of the sintering catalyst is such that particles smaller than 0.074 mm account for more than 80 wt%.
[0008] A method for using a sintering oxidation catalyst for high-proportion magnetic concentrate, wherein the high-proportion magnetic concentrate refers to iron concentrate in which the mass fraction of magnetite in the iron-containing raw material is ≥70%, specifically includes the following steps: 1) A mixture C is composed of magnetite concentrate with an oxidation degree a < 40% at 900℃, sintering oxidant, and basic flux. The weight percentages of mixture C are: 84-89 parts iron concentrate, 2-5 parts sintering oxidant, and 8-12 parts basic flux. A mixture D is composed of magnetite concentrate with an oxidation degree a = 40%-70% at 900℃, sintering oxidant, and basic flux. The weight percentages of mixture D are: 85 parts iron concentrate, 85 parts iron concentrate, and 85 parts basic flux. ~91 parts, sintering oxidant 1~3 parts, alkaline flux 7~13 parts; magnetite concentrate with an oxidation degree a>70% at 900℃, sintering oxidant, and alkaline flux are combined to form mixture E, in which, by weight, iron concentrate is 85~94 parts, sintering oxidant is 0.5~1.5 parts, and alkaline flux is 5~14 parts; with sintered solid fuel as the core, sintering catalyst is coated on its surface to prepare mixture F; The degree of oxidation refers to the real-time mass increment of the iron concentrate oxidation reaction in a temperature-controlled thermogravimetric experimental system, characterizing the Fe content in the concentrate at a specific temperature / time point. 3+ The percentage of total iron (TFe) by mass.
[0009] 2) When magnetite concentrate accounts for ≥70% and <80% of the iron-containing raw material by mass, take 35-55 parts by weight of mixture C, 25-40 parts by weight of mixture D, 10-25 parts by weight of mixture E, and 3-5 parts by weight of mixture F; when magnetite concentrate accounts for ≥80% and <90% of the iron-containing raw material by mass, take 30-50 parts by weight of mixture C, 20-40 parts by weight of mixture D, 15-30 parts by weight of mixture E, and 2-4 parts by weight of mixture F; when magnetite concentrate accounts for more than 90% of the iron-containing raw material by mass, take 20-30 parts by weight of mixture C, 20-45 parts by weight of mixture D, 30-50 parts by weight of mixture E, and 1.5-3 parts by weight of mixture F. 3) Mix mixture C, mixture D, mixture E and mixture F in the mixer according to the above proportions. The mixing time is 3 to 5 minutes. Add the sintering mixture to the sintering trolley, ignite and sinter with exhaust air to obtain the finished sintered ore.
[0010] The main function of sintering oxidants is to promote the combustion of sintering fuel and maintain the oxidizing atmosphere of the material layer, thereby ensuring the normal progress of the sintering reaction. Simultaneously, they promote the formation of calcium ferrite. Under a strong oxidizing atmosphere and suitable temperature, Fe₂O₃ can react with CaO to produce calcium ferrite. Calcium ferrite is a high-strength, highly reducing, and high-quality binder phase, and is a key mineral sought after in modern high-quality sintered ores.
[0011] The main function of sintering catalysts is to adsorb and activate oxygen, reduce the ignition temperature of solid fuel particles, enable them to start burning intensely at a lower temperature, and accelerate the combustion reaction rate.
[0012] Compared with the prior art, the beneficial effects of the present invention are: 1) This invention, based on the differences in the oxidizing properties of magnetite concentrate, adjusts the ratio of sintering oxidant, saves oxidant usage, increases the oxidation degree of magnetite concentrate, improves the production environment of composite calcium ferrite, and increases the sintering utilization coefficient to 1.35 t / hm. 2 The above results show that solid fuel consumption is reduced to below 42 kg / t; the strength of sinter drum is increased to over 83.5%; and the reducibility is increased from 80% to 85%.
[0013] 2) The sintering catalyst in this invention improves the combustion efficiency of solid fuel (carbon), improves the oxidation kinetics of high-proportion magnetite sintering, and enhances sintering production efficiency and sinter quality. Detailed Implementation
[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the specific implementation methods of this invention will be further described below in conjunction with the embodiments. The following embodiments are used to specifically illustrate the content of this invention. These embodiments are only general descriptions of the content of this invention and do not limit the content of this invention.
[0015] Example 1: A high-proportion concentrate sintering oxidation catalyst and its application method include the following steps: (1) Preparing a sintering oxidant: by weight (dry basis), calcium peroxide is 55 parts, magnesium peroxide is 35 parts, potassium permanganate is 5 parts, and calcium ferric acid is 5 parts. The above substances are thoroughly mixed and ground to prepare a sintering oxidant. The particle size composition of the oxidant is 90.6 wt% of particles smaller than 0.074 mm. (2) Preparing a sintering catalyst: by weight (dry basis), dolomite is 60 parts, iron powder is 20 parts, rare earth tailings is 15 parts, and sintering dust is 5 parts. The above substances are thoroughly mixed and ground to prepare a sintering catalyst. The particle size composition of the sintering catalyst is 82.6 wt% of particles smaller than 0.074 mm. (3) Prepare sintering mixtures: Mixture C is composed of magnetite concentrate with an oxidation degree a < 40% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 85 parts, the weight parts of sintering oxidant are 5 parts, and the weight parts of alkaline flux are 10 parts; Mixture D is composed of magnetite concentrate with an oxidation degree a = 40%~70% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 90 parts, the weight parts of sintering oxidant are 2 parts, and the weight parts of alkaline flux are 8 parts; Mixture E is composed of magnetite concentrate with an oxidation degree a > 70% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 92.5 parts, the weight parts of sintering oxidant A are 0.5 parts, and the weight parts of alkaline flux are 7 parts; Mixture F is prepared by coating the surface of sintering catalyst with sintering solid fuel as the core. (4) When magnetite concentrate accounts for 75% of the iron-containing raw material by weight, the weight of mixture C is 55 parts, the weight of mixture D is 25 parts, the weight of mixture E is 15 parts, and the weight of mixture F is 5 parts; when magnetite concentrate accounts for 85% of the iron-containing raw material by weight, the weight of mixture C is 50 parts, the weight of mixture D is 30 parts, the weight of mixture E is 16 parts, and the weight of mixture F is 4 parts; when magnetite concentrate accounts for 90% of the iron-containing raw material by weight, the weight of mixture C is 30 parts, the weight of mixture D is 30 parts, the weight of mixture E is 37 parts, and the weight of mixture F is 3 parts; (5) Mix mixture C, mixture D, mixture E, and mixture F in the mixer according to the above proportions for 5 minutes. Add the sintering mixture to the sintering trolley, ignite and exhaust for sintering, and obtain the finished sintered ore.
[0016] After the application of this invention, the thickness of the sintering layer increased from 750 mm to 950 mm, and the sintering utilization coefficient increased from 1.226 t / hm. 2 Increased to 1.386 t / hm 2 Solid fuel consumption decreased from 47.65 kg / t to 41.83 kg / t; the sinter drum strength increased from 78.83% to 82.15%, and the reducibility increased from 81.85% to 83.64%.
[0017] Example 2: A high-proportion sintering oxidation catalyst for concentrate, its preparation and use method, comprising the following steps: (1) preparing a sintering oxidant, wherein by weight (dry basis), calcium peroxide is 30 parts, magnesium peroxide is 45 parts, potassium permanganate is 15 parts, and calcium ferrate is 10 parts, the above substances are thoroughly mixed and ground to prepare a sintering oxidant, wherein the particle size composition of the sintering oxidant is 91.8% of particles smaller than 0.074 mm. (2) preparing a sintering catalyst, wherein by weight (dry basis), dolomite is 30 parts, iron powder is 40 parts, rare earth tailings is 20 parts, and sintering dust is 10 parts, the above substances are thoroughly mixed and ground to prepare a sintering catalyst, wherein the particle size composition of the sintering catalyst is 88.6% of particles smaller than 0.074 mm. (3) Prepare sintering mixtures: Mixture C is composed of magnetite concentrate with an oxidation degree a < 40% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 89 parts, the weight parts of sintering oxidant A are 2 parts, and the weight parts of alkaline flux are 9 parts; Mixture D is composed of magnetite concentrate with an oxidation degree a = 40%~70% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 91 parts, the weight parts of sintering oxidant A are 1 part, and the weight parts of alkaline flux are 8 parts; Mixture E is composed of magnetite concentrate with an oxidation degree a > 70% (900℃), sintering oxidant A, and alkaline flux, wherein the weight parts of iron concentrate are 94 parts, the weight parts of sintering oxidant are 0.5 parts, and the weight parts of alkaline flux are 5.5 parts; Mixture F is prepared by coating the surface of sintering catalyst with sintering solid fuel as the core. (4) When magnetite concentrate accounts for 70% of the iron-containing raw material by weight, the weight of mixture C is 35 parts, the weight of mixture D is 40 parts, the weight of mixture E is 20 parts, and the weight of mixture F is 5 parts; when magnetite concentrate accounts for 80% of the iron-containing raw material by weight, the weight of mixture C is 32 parts, the weight of mixture D is 35 parts, the weight of mixture E is 30 parts, and the weight of mixture F is 3 parts; when magnetite concentrate accounts for 91% of the iron-containing raw material by weight, the weight of mixture C is 20 parts, the weight of mixture D is 40 parts, the weight of mixture E is 38.5 parts, and the weight of mixture F is 1.5 parts; (5) Mix mixture C, mixture D, mixture E, and mixture F in the mixer according to the above proportions for 3 minutes. Add the sintering mixture to the sintering trolley, ignite and exhaust for sintering, and obtain the finished sintered ore.
[0018] After applying this invention, the sintering layer thickness increased from 750mm to 1000mm, and the sintering utilization coefficient increased from 1.236t / hm. 2 Increased to 1.375 t / hm 2Solid fuel consumption decreased from 47.85 kg / t to 40.68 kg / t; the sinter drum strength increased from 78.83% to 83.96%, and the reducibility increased from 82.89% to 84.86%.
[0019] Example 3: A high-proportion concentrate sintering oxidation catalyst, its preparation and use method, comprising the following steps: (1) preparing a sintering oxidant, wherein by weight (dry basis), 40 parts of calcium peroxide, 40 parts of magnesium peroxide, 8 parts of potassium permanganate, and 12 parts of calcium ferrate are thoroughly mixed and ground to prepare a sintering oxidant, wherein the particle size composition of the sintering oxidant is 92.3% of which are particles smaller than 0.074 mm. (2) preparing a sintering catalyst, wherein by weight (dry basis), 40 parts of dolomite, 30 parts of iron powder, 15 parts of rare earth tailings, and 15 parts of sintering dust are thoroughly mixed and ground to prepare a sintering catalyst, wherein the particle size composition of the sintering catalyst is 86.8% of which are particles smaller than 0.074 mm. (3) Prepare sintering mixtures: Mixture C is composed of magnetite concentrate with an oxidation degree a < 40% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 88 parts, the weight parts of sintering oxidant A are 3 parts, and the weight parts of alkaline flux are 9 parts; Mixture D is composed of magnetite concentrate with an oxidation degree a = 40%~70% (900℃), sintering oxidant, and alkaline flux, wherein the weight parts of iron concentrate are 90 parts, the weight parts of sintering oxidant A are 2 parts, and the weight parts of alkaline flux are 8 parts; Mixture E is composed of magnetite concentrate with an oxidation degree a > 70% (900℃), sintering oxidant A, and alkaline flux, wherein the weight parts of iron concentrate are 90 parts, the weight parts of sintering oxidant are 1 part, and the weight parts of alkaline flux are 9 parts; Mixture F is prepared by coating the surface of sintering catalyst with sintering solid fuel as the core. (4) When magnetite concentrate accounts for 79% of the iron-containing raw material by weight, the weight of mixture C is 45 parts, the weight of mixture D is 30 parts, the weight of mixture E is 25 parts, and the weight of mixture F is 5 parts; when magnetite concentrate accounts for 89% of the iron-containing raw material by weight, the weight of mixture C is 37 parts, the weight of mixture D is 30 parts, the weight of mixture E is 30 parts, and the weight of mixture F is 3 parts; when magnetite concentrate accounts for 92% of the iron-containing raw material by weight, the weight of mixture C is 25 parts, the weight of mixture D is 35 parts, the weight of mixture E is 38.5 parts, and the weight of mixture F is 1.5 parts; (5) Mix mixture C, mixture D, mixture E, and mixture F in the mixer according to the above proportions for 3 minutes. Add the sintering mixture to the sintering trolley, ignite and exhaust for sintering, and obtain the finished sintered ore.
[0020] After the application of this invention, the thickness of the sintering material layer increased from 850 mm to 1050 mm, and the sintering utilization coefficient increased from 1.31 t / hm. 2 Increased to 1.40 t / hm 2 Solid fuel consumption decreased from 45.85 kg / t to 40.01 kg / t; the sinter drum strength increased from 78.83% to 84.66%, and the reducibility increased from 81.54% to 85%.
Claims
1. A sintering oxidation catalyst for high-proportion magnetic concentrate, characterized in that, It is composed of a sintering oxidant and a sintering catalyst. The raw materials for preparing the oxidant include, by weight, 30-55 parts of calcium peroxide, 25-45 parts of magnesium peroxide, 2-15 parts of potassium permanganate, and 2-12 parts of calcium ferrate. The above raw materials are thoroughly mixed and ground to prepare the sintering oxidant. The raw materials for preparing the sintering catalyst include, by weight, 30-60 parts of dolomite, 20-40 parts of iron powder, 10-20 parts of rare earth tailings, and 5-15 parts of sintering dust. The raw materials for preparing the sintering catalyst are thoroughly mixed and ground to prepare the sintering catalyst.
2. The sintering oxidation catalyst for high-proportion magnetic concentrate according to claim 1, characterized in that, The particle size distribution of the sintering oxidant is such that particles smaller than 0.074 mm account for more than 90 wt%.
3. The sintering oxidation catalyst for high-proportion magnetic concentrate according to claim 1, characterized in that, The sintering catalyst has a particle size composition of more than 80 wt% of particles smaller than 0.074 mm.
4. A method of using the sintering oxidation catalyst for high-proportion magnetic concentrate as described in claim 1, characterized in that, Includes the following steps: 1) A mixture C is composed of magnetite concentrate with an oxidation degree a < 40% at 900℃, sintering oxidant, and basic flux. The weight percentages of mixture C are: 84-89 parts iron concentrate, 2-5 parts sintering oxidant, and 8-12 parts basic flux. A mixture D is composed of magnetite concentrate with an oxidation degree a = 40%-70% at 900℃, sintering oxidant, and basic flux. The weight percentages of mixture D are: 85 parts iron concentrate, 85 parts iron concentrate, and 85 parts basic flux. ~91 parts, sintering oxidant 1~3 parts, alkaline flux 7~13 parts; magnetite concentrate with an oxidation degree a>70% at 900℃, sintering oxidant, and alkaline flux are combined to form mixture E, in which, by weight, iron concentrate is 85~94 parts, sintering oxidant is 0.5~1.5 parts, and alkaline flux is 5~14 parts; with sintered solid fuel as the core, sintering catalyst is coated on its surface to prepare mixture F; 2) When the mass fraction of magnetite concentrate in the iron-containing raw material is less than 80% (70% ≤ 70%), take 35-55 parts by weight of mixture C, 25-40 parts by weight of mixture D, 10-25 parts by weight of mixture E, and 3-5 parts by weight of mixture F; when the mass fraction of magnetite concentrate in the iron-containing raw material is less than 90% (80% ≤ 80%), take 30-50 parts by weight of mixture C, 20-40 parts by weight of mixture D, 15-30 parts by weight of mixture E, and 2-4 parts by weight of mixture F; when the mass fraction of magnetite concentrate in the iron-containing raw material is greater than 90%, take 20-30 parts by weight of mixture C, 20-45 parts by weight of mixture D, 30-50 parts by weight of mixture E, and 1.5-3 parts by weight of mixture F. 3) Mix mixture C, mixture D, mixture E and mixture F in the mixer according to the above proportions. The mixing time is 3 to 5 minutes. Add the sintering mixture to the sintering trolley, ignite and sinter with exhaust air to obtain the finished sintered ore.